build/tests: support declaring tests to be manually executed

backend.native/tests/build.gradle

@@ -1500,6 +1500,7 @@ task interop_echo_server(type: RunInteropKonanTest) {
     if (isLinux()) {
         disabled = true
     }
+    run = false
     source = "interop/basics/echo_server.kt"
     interop = 'sockets'
 }

backend.native/tests/interop/basics/echo_server.kt

@@ -2,7 +2,8 @@ import kotlinx.cinterop.*
 import sockets.*
 
 fun main(args: Array<String>) {
-    if (args.size == 0) {
+    if (args.size < 1) {
+        println("Usage: ./echo_server <port>")
         return
     }
 

buildSrc/src/main/groovy/org/jetbrains/kotlin/KonanTest.groovy

@@ -25,6 +25,7 @@ abstract class KonanTest extends JavaExec {
     List<String> arguments = null
 
     boolean enabled = true
+    boolean run = true
 
     void setDisabled(boolean value) {
         this.enabled = !value
@@ -141,6 +142,11 @@ abstract class KonanTest extends JavaExec {
         def exe = buildExePath()
 
         compileTest(buildCompileList(), exe)
+
+        if (!run) {
+            println "to be executed manually: $exe"
+            return
+        }
         println "execution :$exe"
 
         def out = null